Draft gear



Sept. 4, 1928.

w. H. corToN DRAFT GEAR Filed Aug. 29, 1925 2 Sheets-Sheet l lul Sept. 4, 1928.

w. H. COTTON DRAFT GEAR Filed Aug. 29, 1923 2 Sheets-Sheet 2 Patented Sept. 4, 1928.

UNITED STATES PATENT OFFICE.

WALTER H. COTTON, OF CHICAGO, ILLINOIS, ASS-IGNOR T0 UNION' DRAFT GEAR COM- PANY, OF CHICAGO, ILLINOIS, A CORPORATION 0F DELAWARE.

DRAFT GEAR.

Application filed August 29, 1923. Serial N0. 659,865.

The invention relates to draft gears for railway cars, and is of the type in which reliance is had in great measure upon friction for absorbing the stresses incident to draft and buliing. Y

--It's objects are to secure a high vdegree of etliciency, smoothness of: action, certainty of release, economy, of manufacture and durability.I The invention consists in a structure such as is hereinafter described, and as illustrated in the accompanying drawings, in which Fig. lis a detail plan view of the underframi'ng of a car and a central plan section of the improved gear:

Fig. 2 is a view similar to Fig. 1, showing the gear under compression and some of its movable parts in plan and partly broken away;

Fig. 3 is asectional View on the line 3-3 of Fig. 1;

Fig. 4 is a similar View of the gear detached from the car.l showing a slightly modified form of construction; and f Figs. 5 and 6are details in perspective of certain of the elements of the gear.

There is represented at 10, 10, a pair of center or draft sills of a railway car, to each of which is attached a draft lug 11, 11, and a buliing lng 12, 12. At 13 there is shown the butt of a-coupler of ordinary construction, and at 14 the coupler extension, shown in the -form of a yoke or loop ,which encircles the gear. These parts are of any preferred con struction.

' The gear comprises a pair of followers 15, k16, for cooperating, respectively. with the draft and buliing shoulders. Each of these followers is in box form, having side walls 17, 18, and top and bottom walls 19, 20, all of which walls extend'fromtheen'd plate, which takes bearing upon the lugs, and are of such length that the ends of these walls of the two followers abut when the desired limit of the 'compression of the gear is reached, for the purpose of preventing injury to the springs which are enclosed therein.

: Seated against the inner face of the end vwall of each of the' followers is a pair of 'wedge-blocks 21` 22:, and 23, V24, these blocks being preferably in the form of equilateral f' triangles. The outer faces of these vseveral i blocks are, of course-inclined inwardly with respect'to the axis of the gear,.and bear'upon correspondingly inclined faces of wedging friction shoes 25, 26, 27 and 28 which are allke 1n form. The outer or lateral face 29 of each isrparallel to the axis of the gear, and each has an instanding shoulder, ias at 30,-form1ng a seat for a spring, though preferably a vplate 31 is inserted andconstitutes the spring seat. The inner lateral face of each of the shoes 25 to 28,beyondtheshoul der 30, is recessed in concave form to Vaccom- -modate the spring and/.the spring seats named, when the latter arepresen't. Y i Helical springs 32, 33, are interposed between each pair of lshoes 'and each may, as shown, comprise a pair of nested or concentrically assembled springs.

Located upon the axis-of the gear is-anelement 34, the lengthvof whichfis approximately, but not to exceed, the distance between the inner faces of the end wallsfof the followers when the `gear is completelyi compressed. The ends of the element 34 are formedv into heads 3,5, 36, having laterally inclined wedging faces for engagingtheinnerffaces .oif tlie wedge-blocks 21, 22, vand 23, 24.. ,In the, form of construction shown in Fig-3, the element`v 34 is provided throughout its lengthj with a web portion A37, which isv laterally concaveto accommodate the springs .and the several plates 31. In the construction shown inFig. 4, this web is omitted, the heads, 36, being united by top and bottom tie members :38, 39, and there being employed two plates, as 40 (only one of which is shown),;each forming .a seat for'both of the springs32, 33. l

Interposed betweenfthe shoes-25, 27, and the shoes 26, 28, and the adjacent side walls of the followers 15, 16, is-a friction plate 41, 41, the length of which is preferably approximately, and necessarily, not to exceed the distance between the end walls of the two.` followers when the gearis fully compressed. The plates 41, 41, are normally centrally disposed between the ends of the gear,l and they may be interlocked with the element 34 by means of top and bottom plates 42,43,fitf4 ting within recesses 44, 45, in the top and bottom margins of the plates 41, and recesses 46, 47, in the element 34. The upper and lower faces of the element 34 being-of substantial width, the plates 42, 43, may fit snug-1 ly within the recesses therein for the purpose of maintaining them substantially perpendicular to the axis of the gear andinsuring plates with the element 34, both in the comuniformity of ymovement ofv the .friction I' pressive and release movements'of the gear.

Under the influence of buffing stresses the follower 15 is moved baclrwardly, carrying with it the Wedge-blocks 21, 22. The element 34 is forced inwardly and cau-ses the spreading or lateral separation of the triangularl wedge-bloclrs at each end of the gear, this movement resulting in the advance, toward the center of the gear, of all of the shoes 25 to 28, and the consequent compression of the springs 32, 33. The pressure of the triangular wedge-blocks against the shoes urges them laterally, pressing the plates 41, 4l, against the side walls of the followers. As these friction plates travel with the element 34 they necessarily slide upon the side walls of the followers, and there is also sliding movement upon these plates ofthe shoes 25 to 28. Inv addition to the 'friction' developed between these. elements there'is also friction developed between the several wedging faces and between the outer faces of the triangular wedge-blocks and the end walls of the followers.

Upon the relief of bufling stresses the various parts of the gear return to their normal positions, as shown in Fig. 1, under the influence of the springs 32, 33, the release action, however, being sufficiently delayed by friction to prevent shock.

The action of the gearvunder the influence of draft stresses is the same as inbufling, but in the opposite directionlongitudinally.

Various changes in the embodiment of the invention may be made without departing from its scope. For example, the plates 41 may be omitted, permitting the shoes to directly engage the side walls of the followers.

The interlocking of the friction plates 41, 41 with each other and with the 'central member 34 by means of' plates or bars as 42, or otherwise, may be o-mitted as the'friction of the several parts will insure substantial Ipositioningr of the friction plates midway of the ends of the gear when inA release position.

I claim as my invention:

1. In a draft gear, in combination, a pair of chambered followers, a pair of triangular wedge blocks seated against the end walls of each follower, a Central ele-menthaving wedge-shaped ends bearing upon the inner faces of all the said wedge blocks, a friction shoe having a wedging face engageable with the outer face of each wedge block, such shoe having an instanding and inwardlyfacing shoulder,"springs reacting'between the shoes at each side of the gear, a friction plate interposed between the shoes at each side of the gear and the adjacent side walls of the followers, and means movable with said central member for positioning said plates.

Y 2. In a draft gear, in combination, a pair of chambered followers, a pair of triangular Wedge blocks seated against the end walls of each follower, a central element having wedgeshaped ends bearing upon the inner faces of all Vthe said wedge blocks, a friction shoe hat fing face engageable with the oute an i s a sin le i ings reacting between the shoes at each of ".he gear, a friction plate interposed between the shoes at each side of the gear and the adjacent side walls of the followers, and means for interlocking the friction plates withthe central element.

3. In a draft gear, in combination, a pair of chambered followers,`a pair of triangular wedge blocks seated against the end walls of each follower, a central element having wedge-shaped ends bearing upon the inner Vfaces of all the said wedge blocks, a friction shoe having a wedging face engageable with the outer face of each wedge block, such shoe having an instanding and inwardly facing shoulder, springs reacting between the shoes at each side of the gear, a friction plate interposed between the shoes at each side of the gear and the adjacent side walls of the followers, and a cross plate seated in recesses in the friction plates and the central member.

4. In a draft gear, in combination, two pairs of triangular wedge blocks, a unitary element having wedge-shaped ends bearing upon the inner faces of all the said wedge blocks, a plurality of friction shoes, each shoe having a wedging face engageable with the outer face of each wedge block and adapted to move laterally upon compression of the gear, such shoe having an instanding and inwardly facing shoulder, springs reacting between the shoes at each side of the said gear, and means for holding the parts of the mechanism in assembled relation.

5. In a draft gear, in combination, followers having side walls, a friction plate slidably engaging one of the side walls of each follower, a friction shoe at each end of the plate for slidably engaging the plate, wedge means for advancing'the shoes and for pressing them against the plate, the range of longitudinal movement of the shoes being relatively greater than that of the plate, means for yieldingly opposing the advance of the shoes, and means for resisting lateral pressure of said shoes and cooperating wedge means.

6. In a draft gear, in combination, a pair of opposed chambered followers, a pair of friction plates engageable with the side walls of both followers and of less length than the normal distance between the end walls of such followers. a friction shoe engaging each end portion of each plate, each shoe having an inwardly inclined face, a laterally movable wedge block engageable with the inclined face of each shoe, means for moving the wedge blocks laterally outward, and spring means resisting the advance of the shoes.

t riding and inwardly facing 7. In a draft gear, in combination, a pair of opposed chambered followers, a pair of friction plates engageable with the side walls of both followers and of less length than the 5 normal distance between the end walls of such followers, a friction shoe engaging each end portion of each plate, each shoe having an inwardly inclined face, a laterally movable wedge block engagcable with the 1nclined face of each shoe, a double ended wedge of the shoes.

WALTER H. COTTON. 

